Multilayered polymer tubing with braided layer and methods of making and using same

ABSTRACT

A multilayered tube is provided comprising an inner layer of a tube comprising a first polymer, a second layer of a tube comprising a braided layer comprising a metal or a second polymer, and a third layer of a tube comprising a polymer, which can be either the first, second, or still another third polymer. The braided tube layer provides mechanical strength and rigidity to the multilayered tube without adversely affecting the desired chemical or other properties of the inner and outer layers of the tube. A catheter is provided comprising such a multilayered tube. A method is provided for using a catheter for medical diagnostic or analysis, wherein the catheter comprises such a multilayered tube. A liquid chromatography system is provided comprising tubing which comprises such a multilayered tube.

RELATED APPLICATION

[0001] This application claims the benefit of U.S. provisional patent application IMPROVED MULTILAYERED POLYMER TUBING WITH BRAIDED LAYER AND METHODS OF MAKING AND USING SAME, Serial No. 60/354,260, filed Feb. 4,2002, hereby incorporated by reference in its entirety, as if set forth below.

FIELD OF THE INVENTION

[0002] The invention relates to multilayered polymer tubing which includes at least one layer which is braided and methods of manufacturing and using such tubing.

BACKGROUND OF THE INVENTION

[0003] Tubing is used to carry fluids in a wide variety of applications. Among other things, polymer tubing is used to carry fluids in medical applications and devices, analytical applications and devices, and so forth. Multilayered polymer tubing is also conventional, and has been used in a wide variety of applications. For example, U.S. Pat. Nos. 6,293,312 B1, 6,180197 B1, 5,743,304, 5,641,445, 5,638,871, and 5,630,806 all disclose multilayered polymer tubing, using various polymers for various applications. The foregoing patents are hereby incorporated by reference as if fully set forth herein. In addition, U.S. Pat. Nos. 5,855,977, 5,827,587, 5,756,199, 5,658,670, and 5,656,121 disclose various multilayered polymer composites and methods of making same. The foregoing patents are hereby incorporated by reference as if fully set forth herein.

[0004] A common problem with conventional multilayered tubing is that a unique combination of properties is sometime desirable for a particular application. For example, in high pressure liquid chromatography (HPLC) applications, a combination of high pressures with the chemical solvents used in the chromatographic analysis means that only a limited number of polymers may be appropriate. For higher pressures or applications where structural strength, torsion resistance, lubricity, or other characteristics are required for a given application, there simply may not be a suitable polymer which can be easily used for tubing in the application. Moreover, biocompatibility is often an important and desirable characteristic, especially in many medical applications and devices, as well as in many HPLC and other analytical applications.

[0005] Attached as Appendix 1 hereto are materials describing the various properties and characteristics of several different polymers used in HPLC tubing. Appendix 1 is hereby incorporated by reference as if fully set forth herein. Attached collectively as Appendix 2 hereto are materials describing extruded polymer tubing made from a variety of different polymers and having a variety of useful applications. Appendix 2 is hereby incorporated by reference as if fully set forth herein. The materials of Appendices 1 and 2 describe conventional tubing which is commercially available from Upchurch Scientific of Oak Harbor, Wash.

SUMMARY OF THE INVENTION

[0006] In one preferred embodiment of the invention, there is a multilayered tube comprising an inner layer of a tube comprising a first polymer, a second layer of a tube comprising a braided layer comprising a metal or a second polymer, and a third layer of a tube comprising a polymer, which can be either the first, second, or still another third polymer. The braided tube layer provides mechanical strength and rigidity to the multilayered tube without adversely affecting the desired chemical or other properties of the inner and outer layers of the tube.

[0007] In one preferred embodiment ofthe invention, the inner layer comprises polyetheretherketone (PEEK), the braided layer comprises metal (such as any one of the following: 316 stainless steel, 400 series stainless steel, gold, silver, platinum, copper, and similar metals and/or alloys), and the outer layer comprises PEEK. In yet another alternative embodiment of the invention, the inner layer comprises polyethersulfone (PES), the braided layer comprises any one of the materials selected from the following group: aramid fibers (such as those sold under the trademarks KEVLAR and NOMEX, nylon, and the like), graphite fibers, glass fibers, and similar fibrous materials, and the outer layer comprises PES.

[0008] In yet another alternative embodiment, a catheter (or other medical or diagnostic device) comprises a multilayered tube substantially as described herein, where at least one layer is braided. In still another alternative embodiment of the invention, an HPLC system comprises at least one multilayered tube substantially as described herein.

BRIEF DESCRIPTION OF THE DRAWING

[0009]FIG. 1 is a cross-sectional view of a multilayered tube in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0010] Referring to FIG. 1, a multilayered tube 1 in accordance with the present invention is shown. Tube 1 includes an inner tube 5, a second, braided tube 10, and a third, outer tube 15.

[0011] In one preferred embodiment of the invention, the multilayered tube 1 has an inner tube 5 layer 5 made of PEEK. We have found that PEEK offers good solvent resistance and mid pressure range capabilities. Thus, PEEK is useful for a variety of applications with demanding conditions. Disposed around the inner PEEK layer 5 is a second layer 10 of tubing that is braided. This second braided layer 10 of tubing can be made from any one of a number of materials. The braided layer 10 can be made of fibers of various materials, including aramids, graphite, glass, and other fibrous materials, or can be made of metal, such as stainless steel, gold, silver, platinum, copper, or other metals. Finally, disposed around the second, braided tubing layer 10 is a third layer 15 of tubing. In a preferred embodiment of the invention, this third layer 15 of tubing is made of PEEK and is extruded over the two inner layers of the multilayered tube 1.

[0012] In one particular example of various illustrative embodiments of the invention, we used an inner layer 5 made of PEEK with an inner diameter of 0.010″ and an outer diameter of 0.020″. This inner layer 5 was extruded through conventional means. We then placed a braided layer 10 made of 316 stainless steel around the inner layer 5. The thickness of the second, braided layer 10 was 0.003″. Finally, we extruded a third, outer layer 15 around the first two layers, with the third outer layer 15 made of PEEK with an inner diameter of 0.026″ and an outer diameter of 0.062″. It will be appreciated by those skilled in the art that the dimensions of the various layers of the multilayered tube 1 may be varied depending on the need to accommodate various pressures to which the resulting tube 1 will be exposed, and/or depending on the desired flexibility or rigidity of the resulting tube 1, or other properties or characteristics.

[0013] Braiding various materials has been used for many years. The braided layer 10 can be used to add strength or rigidity as desired to the inner layer 5 of tubing. The braided layer 10 of tubing in various illustrative embodiments of our invention allows the resulting multilayered tube 1 to operate at substantially higher pressures and under more difficult conditions than would be the case without the braided layer 10. Braiding equipment is commercially available from a number of manufacturers. We have used a Wardwell Rapid 16 Carrier Special Braider that was re-worked by Lloyd and Bouvier of Clinton, Mass.

[0014] In another, alternative embodiment ofthe invention, fluoropolymer materials may be used for the inner and outer layers of the multilayered tube 1. Such materials offer high solvent resistance and are therefore particularly useful in certain applications where other materials would quickly corrode. In one particular embodiment, an FEP layer having an inner diameter of 0.020″ and an outer diameter of 0.040″ was used as the substrate, or inner layer 5. A braid 10 made of 316 stainless steel with a layer thickness of 0.003″ was then made around the first inner layer 5. Finally, an outer layer 15 made of FEP and having an inner diameter of 0.046″ and an outer diameter of 0.062″ was used as the third, outer layer 15 of the multilayered tube 1.

[0015] While the present invention has been shown and described in its preferred embodiment and in certain specific alternative embodiments, those skilled in the art will recognize from the foregoing discussion that various changes, modifications, and variations may be made thereto without departing from the spirit and scope of the invention as set forth in the claims. Hence, the embodiment and specific dimensions, materials and the like are merely illustrative and do not limit the scope ofthe invention or the claims herein. 

We claim:
 1. A multilayered tube substantially as described above.
 2. A tube according to claim 1 wherein said tube comprises a braided layer consisting essentially of a material selected from one of the following: aramid fibers, graphite fibers, glass fibers, stainless steel, gold, silver, platinum, and copper.
 3. A catheter comprising a multilayered tube substantially as described above.
 4. Using a catheter for medical diagnostic or analysis, wherein the catheter comprises a multilayered tube substantially as described above.
 5. A liquid chromatography system comprising tubing which comprises a multilayered tube substantially as described above. 